Systemic effects of oral tolerance in bone healing

• Published in: Scientific reports Vol. 13; no. 1; p. 6296
• Main Authors: Costa, Bruno Henrique, Rezende, Alisson Kennedy, Costa, Lais, Neves, Gabrielle Fernanda Monteiro, Shimano, Antônio Carlos, de Oliveira Penoni, Álvaro, Carvalho, Claudia Rocha, Costa, Raquel Alves, de Alvarenga, Erika Costa
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18-04-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/250; 631/250/24; 631/250/256; 631/250/590; 631/250/808; 631/443; 631/443/63; 631/443/811; 692/698/1671; Animals; Bone growth; Bone healing; Computed tomography; Fracture Healing; Fractures; Fractures, Bone; Humanities and Social Sciences; Immunization; Immunological tolerance; Inflammation; Injection; Mineralization; multidisciplinary; Osteogenesis; Rats; Rats, Wistar; Science; Science (multidisciplinary); Tibia; Tibia - diagnostic imaging; Tibia - injuries; Wound healing; Zein; Zein - pharmacology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-33591-4

Bone fractures cause acute inflammation that, despite being important for initial repair, may delay the healing of the damaged bone. Parenteral injection of dietary protein has been shown to decrease inflammation and accelerate the repair of skin wounds and other inflammatory pathologies. Thus, our aim was to evaluate whether the intraperitoneal (i.p.) immunization with zein, an abundant protein in rodent chow, would favor bone healing. Wistar rats received i.p. immunization: saline (SG), adjuvant (AG) and zein associated with adjuvant (ZG). Then, a 2 mm of defect bone was performed on the right tibia, and on days 7, 14, 28 and 45 thereafter, analyses were performed. The results showed that the injection of zein reduced inflammation without impairing bone mineralization. Moreover, biomechanical tests demonstrated higher levels of maximum force (N) in ZG, indicating better mechanical resistance in relation to the others. The computerized tomography also indicated lower levels of medullary content in the ZG than in the SG, suggesting the absence of trabeculae in the medullary region in the ZG. These findings suggest that the injection of zein in previously tolerated animals may improve bone repair, leading to mechanically functional bone formation.